A transparent transmission method for 10000M Ethernet signals in optical transmission network

Abstract

The invention discloses a method for transparently transmitting 10 Gigabit Ethernet signals in an optical transmission network, which uses a first asynchronous mapping method to transparently transmit 10 Gigabit Ethernet signals; wherein, the construction of the first asynchronous mapping method includes the following steps : A1. using any reserved value of the payload structure identifier to indicate the first asynchronous mapping mode; A2. constructing the optical channel transmission unit frame of the first asynchronous mapping mode, and using at least 3 bits pre-define the filling status of the positive and negative adjustment bytes, and add a negative adjustment byte in the overhead area of ​​the payload unit of the optical channel, and add a positive adjustment byte in the payload structure; A3. Using the reference clock, construct The frequency of the overclocked optical channel transmission unit frame is 11.0491Gbit / s±20ppm. By adopting the above solution, the complete 10GELAN signal can be transparently transmitted in the optical transmission network in the way of asynchronous mapping, and fully adapted to the frequency deviation of the client signal.

Description

Technical field [0001] The present invention relates to the transmission of Ethernet services through an optical transport network (OTN), in particular to a 10 Gigabit Ethernet (10GE LAN, 10GE LAN, also known as 10GE Ethernet) signal, which is used in the optical channel of the optical transport network The method of transparent transmission in the OPU2 payload area of ​​the transmission unit. Background technique [0002] Optical Transport Network (OTN) is an optical transport specification formulated by ITU-T. It is mainly composed of OPUk (optical channel payload unit, optical channel payload unit), ODUk (optical channel data unit, optical channel data unit) and OTUk (optical channel transport unit, optical channel transport unit) and other different levels of encapsulation, where k =1, 2 or 3, representing different rate levels. These three OTU rates correspond to their ODU and OPU rates respectively. The specific conditions are detailed in the ITU-T G.709 optical transport n...

AI Technical Summary

Problems solved by technology

Considering that OPUk itself has a frequency difference of 20PPM, the customer signal that can be tolerated is ±45ppm, while the frequency deviation of 10GELAN services is up to ±100ppm, so asynchronous mapping cannot be performed

[0014] If synchronous mapping is used, that is, the OPU2 clock is locked to 10GELAN services, the frequency offset problem can be ignored, but the scalability is relatively poor, and it can only be used for point-to-point connections, or asynchronous crossover at intermediate nodes, and cannot support synchronous crossover

Therefore, this adapted rate cannot enter the crossover network for synchronous crossover, because the synchronous crossover network requires the same ODU clock, and the ODU clock for synchronous mapping comes from 10GELAN, and these 10GELANs are often heterogeneous

[0015] For the bit-agnostic (Agnostic) CBR mapping method, although the undefined overhead byte can be used to indicate the actual transmission byte, which can better adapt to the frequency difference problem, it cannot indicate the specific position of the filling byte, and cannot be used in the payload. Evenly distribute stuffing bytes in the area, so a larger buffer area is needed to accommodate the maximum frequency difference between 10GELAN and OPU2 payload area

[0016] In addition, since the number of bytes in the OPU2 payload area is 3808×4=15232 bytes, about 13 bits are needed to indicate its filling status. When there are other cascade applications, more bits are needed, which requires more OPU overhead bits

Different application scenarios require different overhead bytes for monitoring and management; for example, in the case of virtual concatenation, three overheads in columns 1, 2, and 3 of column 15 in the OTU frame structure are required for indication. Mapping methods with more OPU overhead are also unacceptable

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